Dose-response efficacy of a new estradiol transdermal matrix patch for 7-day application: a randomized, double-blind, placebo-controlled study

Abstract

New estradiol (E₂) transdermal matrix patches developed for once-a-week application, releasing 25 μg E₂ (7D-25) or 50 μg E₂ (7D-50) daily, were investigated in comparison with a placebo patch and the twice-weekly parent patch releasing 50 μg E₂ (Derm-50) daily. Three hundred and eleven postmenopausal patients suffering at least seven hot flushes daily were randomly assigned to the four parallel groups and treated continuously for 12 weeks without progestin opposition.

The daily number of hot flushes significantly decreased in all groups. At the 12th week the decrease from a baseline average of eight to nine episodes per day was 78% with 7D-25, 93% and 97% respectively with 7D-50 and Derm-50, and significantly (p < 0.001) lower with placebo (59%). Comparable efficacy was observed in terms of severity of hot flushes, Kupperman Index and patient self-rated overall efficacy.

Minor systemic adverse events occurred in 10.0%, 8.8%, 16.9%) and 13.5% patients in the placebo, 7D-25, 7D-50 and Derm-50 groups respectively. Occasional mild and transient itching and/or erythema at the site of application was reported by a few patients, with no difference between groups or between once-weekly or twice-weekly application.

In conclusion all E₂ patches were significantly more effective than placebo in relieving climacteric symptoms in a dose-dependent fashion and all were well tolerated.

Key Words:

• Transdermal Estradiol
• Hormone Replacement Therapy (HRT)
• Randomized Controlled Clinical Trial
• Matrix Patch